Footnotes:(1) The comparability of historical labor force data has been affected at various times by methodological and conceptual changes in the Current Population Survey (CPS). For an explanation, see the Historical Comparability section of the Household Data technical documentation provided at http://www.bls.gov/cps/eetech_methods.pdf.

SOURCE: Current Population Survey, U.S. Department of Labor, U.S. Bureau of Labor Statistics.